


a lesson for the professor

by WattStalf



Series: Commissions [43]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Anal Fingering, Anal Sex, Blow Jobs, Cunnilingus, Double Penetration, F/F, F/M, Foursome - F/F/M/M, M/M, Multi, Nipple Play, Spitroasting, Threesome - F/M/M, Vaginal Fingering, Vaginal Sex, commission
Language: English
Status: Completed
Published: 2019-11-28
Updated: 2019-11-30
Packaged: 2021-02-18 06:44:23
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 6,085
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21590227
Author URL: https://archiveofourown.org/users/WattStalf/pseuds/WattStalf
Summary: Dimitri shares his wife with his beloved retainer, and later, Dedue invites his own wife along, all for the purpose of teaching Byleth lessons of pleasure.
Relationships: Dedue Molinaro/My Unit | Byleth, Dimitri Alexandre Blaiddyd/Dedue Molinaro/My Unit | Byleth, Dimitri Alexandre Blaiddyd/Dedue Molinaro/My Unit | Byleth/Mercedes von Martritz, Dimitri Alexandre Blaiddyd/My Unit | Byleth, Mercedes von Martritz/Dedue Molinaro, Mercedes von Martritz/My Unit | Byleth
Series: Commissions [43]
Series URL: https://archiveofourown.org/series/1325462
Comments: 1
Kudos: 71





	1. Chapter 1

**Author's Note:**

> Chapter 2 will have Mercedes

Dimitri and Dedue have always been close, much closer than a lord and his retainer, even, but Byleth gets the privilege of seeing just how close they are after she and Dimitri are married. Which is useful to her, as she is still figuring out how certain aspects of her marriage should work. Despite being a little bit older than the two, she doesn’t have experience with things like that, and she is grateful for any help that she can get in that department.

Dedue knows what his liege likes, and Dimitri is more than willing to share with someone as close to him as Dedue, just as Byleth is more than accepting of how close the two of them are. A night is set aside for her lesson, and Mercedes is just as willing to allow it to happen. She won’t be able to join them, but the possibility of her joining them in the future is still there, and Byleth can’t help but admit she’s a little bit excited for that as well.

Either way, the night arrives, and Byleth and Dimitri are alone in their room when they hear a knock, and let Dedue in. He’s respectful as ever, bowing for his king and queen, before Dimitri tells him that formality isn’t necessary tonight. Instead, he says, he thinks Byleth is ready to get started, and she is quick to agree.

She strips down for him, trying not to be shy in regards to getting undressed in front of a man other than her husband. It’s Dedue, so she knows that she has nothing to worry about, and if what she has been promised is true, he’s going to make her feel absolutely amazing before the night is over, something that she is really looking forward to. What he’s going to do for her is both help her pleasure Dimitri, but also pleasure her, in a way that she has never felt before.

When it comes to sharing his wife, Dimitri can’t allow Dedue to have her cunt. There’s too much of a risk that way, and any children that she has have to be his, not only to avoid a scandal, but because he is in need of legitimate heirs. That’s no problem for Dedue though; there are other things that he can do for her, things that she hasn’t experienced and things that he thinks she’ll like very much.

Dimitri is happy to simply watch at first, as the Dedue works at getting Byleth prepared. He instructs her get on her elbows and knees on the bed, and she does as told, face pressed into a pillow to hide any nerves that might be lingering in her expression. Dedue has brought lubricant for this, well-prepared as ever, and as he gets his fingers slick, he says, “You might need a lot of this, so I’m going to use a lot. Better to be safe than sorry, I would never want to do anything to hurt you.”

Strong and stable, dedicated and cautious. There are a lot of things to admire about him, she thinks, and she knows that Mercedes is a very lucky woman. She can’t help but wonder how many nights they’ve spent together doing something like this, and all the things that he’s able to do to his wife when he has no limitations. But then she feels a hand on her, as he spreads her asscheeks, and then a cold finger prodding at her.

She winces, knowing that it’s only cold because of the lubricant, and that he will slowly begin to warm back up, especially as he fingers her. Byleth has never done anything like this before with Dimitri, the two of them always keeping it simple, and she hopes that she is able to learn a lot of things to pleasure her husband, so that sex won’t ever have to feel like an obligation for heirs. She wants him to enjoy himself as much as possible, and wants to be able to enjoy herself at the same time.

Dedue prods at her with one finger until he begins to work it inside of her, and she tries not to let herself tense up. She’s been told already that trying to relax is an important part of this, and that resistance will only lead to further pain. If it’s too uncomfortable, she can always say something he will stop right away, but as long as she can hold out, she wants to, and she takes deep and steady breaths, not allowing herself any unneeded tension.

Just one of his fingers is large enough on its own, and she knows that his cock must be quite a bit larger than that. She knows that he will be bigger than Dimitri, and that makes her a little bit nervous as well, but he’s already promised her that he will make sure she’s more than adequately prepared to properly take him. He’s even promised her that, if she isn’t ready tonight, they can take their time with preparations, repeating this process nightly until she’s able to take him, but Byleth is determined to be ready for him tonight.

Slowly, he eases one finger inside of her, until he’s completely buried it, and she lets out a long breath, trying not to hold onto it for too long. Her relaxation is key, she reminds herself, and Dedue remains still for a moment, just to make sure that she’s not experiencing any discomfort.

“How is that?” he asks her.

“It’s...strange,” she admits, “but it’s not bad, not at all.”

“Good,” he replies in a warm voice, and he slowly curls his finger, until she’s gasping out in surprise. The sensation is an odd one, but not at all unpleasant, and her gasp soon fades into a moan as she starts to truly understand why it is that people do this. Though she’s been willing to go along with it, she’s never  _ gotten _ it before, only known that it was a thing, and that she should try it before she wrote it off completely. Now, she’s very glad that she is.

His first finger is just the beginning, and after he’s given her ample time to adjust to that, there is another following it, his second finger pushing next to the first so as to stretch her further. Byleth whimpers, pressing her face further against the pillow to muffle herself. She doesn’t meant to be embarrassed by how expressive she is, but that’s outside of her control, and she isn’t used to behaving this way around anyone other than her husband. Of course, she knows that she should be well past the point of embarrassment by now.

With two fingers buried inside of her, Dedue can spread them apart slowly, all to further prepare her. Her moans become more frequent, as he alternates between spreading his fingers and hooking them, working them inside of her until she begins to think that he could finish her off like this, before he ever properly fucked her. But he doesn’t, stopping after a while, just as she’s really starting to get comfortable with it and just as she’s starting to crave more.

“I think you might be ready now,” Dedue says. “What do you think?”

“I think so,” she replies, her voice so muffled that she’s hardly coherent, and Dedue pulls gently on her shoulder. Byleth gets up, sure that her face must be a deep red by now, and she has a hard time looking at either of the men. But they have to get into position for what comes next, and she stands up, her legs shaking as she goes to join Dimitri.

Dedue stands behind her, bending her over so that he can properly fuck her, and putting her at eye level with Dimitri’s erection. Byleth wastes no time in wrapping her lips around the head of her husband’s cock, earning a low and needy moan from Dimitri as she does so. He rests a hand on her head as she begins to suck him off, but she intends to get more guidance before she goes forward, as she doesn’t know much about this.

Dedue is here to help her, after all, and he says, “Make sure your take his majesty slowly, so that he has time to savor each sensation.” It’s odd to get such advice from him, but if there’s anyone she would trust with matters of Dimitri’s pleasure, it’s Dedue.

So Byleth follows his instructions, rolling her tongue over the tip of Dimitri’s cock and remaining like this for a moment, just to hear the way it makes him moan and cry out for her, his hand heavy on the back of her head as he pats her with his approval, already finding it difficult to simply speak about it. She continues slowly, moving her mouth forward as she draws him deeper, and as she does, she feels the tip of Dedue’s cock pressed against her hole.

While she’s been busying herself with pleasuring Dimitri, he’s been using more lubricant to get himself prepared, and now that he is ready, he grabs hold of her hips to keep her steady. Byleth hardly has to remind herself to relax when she’s too focused on her other task, but she knows that if she does tense up too much, then it will only cause her further discomfort. She’s still a little nervous about doing this for the first time, but she is determined to see this through to the end.

It felt so good before, that she can only imagine how good this will feel once she’s used to it. And slowly, Dedue’s grip on her hips tightens as he begins to push forward, steadily fitting his large cock inside of her. Though two of his fingers made for quite the feat, he’s a bit bigger still than that, and Byleth freezes for a moment, having to clear her mind before she can move forward with Dimitri.

At first, she thinks it might be too much, and she considers pulling back so that she can tell Dedue as much, but she takes a few deep breaths, allowing herself to relax and try and take it, and soon enough, that patience begins to pay off. Her body begins to grow used to the fullness and she stretches around him so that she can take him, and so that he can fit snugly inside of her.

Dedue moans, low and quiet and almost breathless, but he doesn’t move, remaining still inside of her so that she can take all the time she needs to grow used to him. And Dimitri remains patient until she can move forward again, drawing him deeper into her mouth once more, and rolling her tongue along the base of his cock. He groans in surprise as she resumes, gripping the back of her head for a moment before loosening his grip and patting her again.

“Good job,” Dedue speaks up, having finally regained his voice. “If you keep it up like that, then you’ll be able to satisfy him without issue.”

Byleth can’t respond to him, so she simply keeps up the work, waiting for Dedue to finally resume his portion. When he does, his first thrust is shallow and gentle, a test to make sure that she can handle it. She shows no signs of discomfort, so he gives another thrust, and then another, until he’s sure that he can truly begin fucking her. Still he moves his hips slowly, with a steady rhythm that allow her to keep up her own pace as she sucks off her husband.

Dedue begins to steadily push her forward with each thrust, until she’s taken Dimitri so deep in her mouth that she’s done all she can manage. Without any instructions on what to do from here, she begins bobbing her head, matching the pace of Dedue’s thrusts until he gets the hint to speed things up a little, pushing her back and forth until he is controlling the pace at which Dimitri fucks Byleth’s mouth.

Dimitri’s moans grow more erratic, until he seems to be hardly hanging on, and Byleth does not want to stop until she’s made him go weak with desire, until he’s calling out her name as he comes. That is what she wants, but neither let her keep it up for much longer, and Dedue pauses after receiving some sort of cue from Dimitri, who holds Byleth’s head still so that she cannot follow him when he pulls away.

“I’m already so close,” he admits, and he is so breathless that that much is evident. “Just give me a moment to catch my breath, and then I want to keep going...I just don’t want to finish in your mouth.”

Byleth understands his reasoning for this. It would be a waste, with his need for an heir and all that, and she certainly doesn’t mind. Not only is it much preferable to swallowing, but to be able to take both men at the same time from either side sounds absolutely wonderful, and though she wouldn’t have asked for it on her own, she’s glad that it’s being offered to her.

Dedue has to pull out of her for the moment, to shift their positions, but he lays down on the bed, inviting her to get on top of him and sink back down onto his cock. She’s surprised that he’s holding out so well, certain that he would have shown some sign of weakening by now, but he holds fast, determined to ride this out until the very end. Byleth feels as though she could lose control at any moment, but fights to hold on until the end as well, wanting to make sure that she can not only pleasure the other two, but also get as much out of this as possible.

He holds her steady as he helps her sink back down onto him, and it’s a comfortable fit now, feeling his big cock filling her from behind. As she lays back, impaled on Dedue, Dimitri seems to have finally relaxed himself enough that he is ready to continue. Following them onto the bed, he gets in front of the two of them, kneeling at just the right level to push inside of Byleth.

“Are you ready for me here?” he asks, pausing just before he pushes into her.

Normally, she might require more preparation, and usually Dimitri spends a fair amount of time helping her through this, nearly as much time as Dedue spent on her ass, but she’s already so turned on that she doesn’t feel like it’s necessary, not that she would turn him down if he insisted. But when she says, “No, I’m ready, I…I want it,” he takes her word for it, and that’s even better.

Dimitri holds onto her as well, as he pushes forward with a low groan. He still takes this part slow, just to be on the safe side, but there is a strain in his face that he says he would rather not hold back at all, that it’s hard for him to do so. She would tell him that he has nothing to worry about except words begin to fail her as soon as he penetrates her. As it turns out, taking both men from either side is even more overwhelming than she expected it to be, and she lets out a low and needy moan, in place of speaking.

Still, he takes this as the encouragement he needs to keep going, pushing further forward until he’s buried himself in her cunt, exhaling as he does. There is a pause, and she can only feel the fullness she gets from the two of them, before they begin to move. Dimitri is the first to thrust, and Dedue remains still as he finds his rhythm, but once he’s steady, Dedue is there to match him.

The two of them going back and forth is more than Byleth can bear, and she suddenly finds her self-control slipping rapidly. Gasping out, crying out for both of them, she struggles and fights to hold on for just a little bit longer, but it seems that she doesn’t have much of a choice. Her body betrays her, and before she knows it, she’s coming and harder than she can ever remember before.

That is all it takes to send Dimitri over the edge, and he thrusts frantically into her, losing his rhythm for that last moment, until he finishes with one final thrust. He comes inside of her with a low groan, finishing just a few seconds after she does. While the two of them are trying to recover from their orgasms, Dedue gives a few shallow thrusts up to finally finish himself off, having managed to hold out all the way until the end. His moan is deep and he comes in Byleth as well, and the sensation is pleasant and comforting.

They separate as soon as they are able to think clearly enough to do so, and lay together, side by side on the bed. The three of them are breathless for some time after this, and it takes them time before they’re able to speak again. When they are, Dedue says, “I hope that was satisfactory for both of you.”

“You have nothing to worry about,” Dimitri replies.

“I agree,” Byleth says. “And thank you so much for all your help. It was wonderful to get to experience such new things, and to be able to do more for Dimitri. It’s just a shame your wife was busy…”

“Yes,” Dimitri agrees. “We’ll have to make sure Mercedes can make it along next time, alright?”

“I’m sure she won’t want to miss it,” Dedue replies with a warm smile that he rarely shows, one that he only reserves for those closest to him. He takes his leave then, but Byleth can only think about how excited she is for next time.


	2. Chapter 2

“That sounds like such a lovely time,” Mercedes says, with a bright smile on her face. It will never cease to surprise Dedue just how sexually open his wife is. She has always had an air of innocence about her, one that made it seem as though such matters would be completely beyond her.

Despite being the oldest in their class, seeming so innocent, and even ditzy at times, often made her feel like one of the younger members of the class, and the things that made her seem older- such as her motherly instincts- were not things that suggested such a side to her. Dedue fell in love with her kind heart and open mind and genuine interest in him, but he never expected this side to come along with all of that.

Not only did she seem too innocent, but she was one of the most pious people that he had met in Fodlan, outside of the ones working directly for the church. Though Dedue has never been fully familiar with the church’s teachings regarding sexuality, he would have assumed that being a devoted follower would mean conforming to the most normal of the norm, perhaps seeing no use for sex outside of the purposes of procreation. He can’t speak for any other devout believers, but for Mercedes, that is not the case. Not even a little bit.

Her acceptance of his close relationship with Dimitri is enough of a surprise, but her willingness and excitement to assist them with their former professor’s “lessons” on pleasure is another thing entirely. She is so open-minded that she doesn’t bat an eye, and even confesses that, if Dedue is going to be involved, she would like to be involved eventually as well. The professor is beautiful and Dimitri is so striking, so if there is a chance for her to assist as well, she would love to. Though the first time comes at an inconvenient time for her, Dimitri and Byleth personally request that Dedue invite her for the second time, and she is overjoyed to hear how welcome she is.

In the meantime, Dedue entertains her with the story of the night she missed, able to see how much it excites her to hear about his night with the royal couple. She surprises him even now with her enthusiasm, and he’s glad that the four of them will be able to get together. He looks forward to getting to spend that time with them, and getting his turn with Dimitri’s wife once again, as well as seeing their wives together.

~X~

Byleth is pleased to hear that Mercedes will be able to join them for the next lesson, and hopes that this is a sign that this will become a more regular thing. Sex with Dimitri is pleasurable enough on its own, and even more so since her first lesson, but there is something about the other couple that draws her to them, something that she can’t expain. Perhaps it’s the newness or the taboo to the idea, but whatever the case, she suspects that she won’t ever be able to get enough of it.

After a rather impatient wait, the night is finally upon them, and the other couple comes to their room, just as they agreed upon. Mercedes smiles so bright that it causes Byleth’s heart so skip a beat, and the first thing she says is, “Thank you both so much for having me. I’m sorry I couldn’t make it last time, it sounds like it was a lot of fun!”

“We’re very glad to have you here,” Byleth replies, already wondering where they’re going to start, and what they can do from here. It will be her first time with a woman, which would be exciting enough on its own, but is even more so because it’s Mercedes.

Byleth has always had an interest in her student, the only one that was actually older than her. There are a lot of things about Mercedes that she finds attractive, and she considers herself lucky to be able to have this night with her.

“Do you want to get started?” asks Mercedes. “I have some ideas to start with that I think will be really fun!”

“Of course,” Byleth says, and the men agree with her. Neither of them mind that the two of them are going to start on their own, and will patiently watch from the sidelines until it is their turn to join in.

“I want to show you how good another woman can make you feel,” Mercedes says, her voice dropping to a murmur, and the tone is like nothing Byleth has ever heard from her before. It makes her knees with, and it’s all she can do to keep her hands from shaking as she begins to undress herself for Mercedes. Dedue helps Mercedes out of her own clothes, and Byleth can’t help but stare at the other woman’s body.

There is a softness to it that Byleth doesn’t have, with all her mercenary training and the scars from unfavorable battles. In comparison to her, Mercedes is nearly perfect in every way. It would be hard not to be jealous, but Byleth is just glad to be able to admire it so much, from up close. Dedue is a lucky man to be able to see this every night, she thinks.

Mercedes has Byleth lay down, climbing on top of her and pressing her lips to hers immediately. Byleth moans into her mouth, surprised by the sudden passion of the kiss, but Mercedes does not let up. While she kisses her, a hand begins to drift down Byleth’s body, and Byleth squirms under her touch. Her hand is pleasantly warm as it explores Byleth’s body, and she returns the kiss with fervor, encouraging her to continue.

When Mercedes breaks the kiss, she says, “I can do a lot more to make you feel good. Do you have anything you want me to do, or should I just choose?”

“Y-you can choose,” Byleth responds, still breathless from their kiss and entirely unsure of what she actually wants Mercedes to do to her. Better to just let her take the lead entirely, since this is supposed to be Byleth’s chance to learn, after all.

With a warm and gentle smile, Mercedes nods before leaning down to press her lips against Byleth’s neck. Byleth squirms as she feels Mercedes’ lips against her skin, trailing kisses all the way down her neck until she’s scooting down further and kissing down, across her shoulders and then further down to her chest. Her breath grows short and rapid, biting her lip as Mercedes moves further and further, until she’s wrapping her lips around one of Byleth’s nipples.

“A-ah!” she whimpers, surprised at how overwhelming the slight contact is. It’s good, it’s really good, and the heat building in her core grows more intense. Mercedes looks up at her from under her lashes, the look in her eyes saying that she understands exactly how good this must feel for her. Of course she does; these are things another woman would understand best, after all, and that’s exactly what Mercedes is trying to show her.

Byleth had never before realized just how sensitive she is, but now, when Mercedes flicks her tongue over her nipple, she arches her back and cries out in pleasure, overwhelmed by such simple sensations. Whimpering, she can only lay back and enjoy it, her head swimming with pleasure, leaving her completely blind to anything other than what Mercedes is doing to her.

And while she uses her lips and her tongue on one of Byleth’s nipples, her other hand still roams over her body, finding her other breast to give it a light squeeze, before she begins pinching and toying with the nipple. Having both stimulated at once is almost too much for Byleth, and she moans, loud and pathetic as she briefly forgets how to think at all. It’s one of the most intense sensations she’s ever felt, and to know that this is just the beginning for tonight is an absolutely amazing thing to remember. Dedue and Dimitri are both still only watching, so it’s hard to imagine how things will be when it’s the four of them, since this is how it is with just Mercedes.

Byleth’s hands clench at either side of her, gripping the sheets in her balled fists as she holds on, not sure what else to do with her hands right now. She squirms and writhes, and Mercedes toys with both of her nipples until she feels that she is at her very limit. Just when she is beginning to think that she will be able to come from this stimulation alone, one of the other woman’s hands begins to drift below her breast, and finds its place between her legs. Byleh lets out a sharp cry to be suddenly touched like this, and as Mercedes begins to finger her, she pulls her face back, smiling up at her again.

“This will feel even better,” she assures her. She moves the hand back up to her breast, while her other hand moves to where her mouth just was, and she toys with her nipple with both hands. Mercedes keeps her hands in place while she leans down further, moving until her face rests between Byleth’s legs, and she can feel her warm breath, whimpering in anticipation. Mercedes kisses a trail up the inside of one of her thighs, until she reaches her cunt, slowly and teasingly working her tongue to Byleth’s hole, teasing outside until she has Byleth nearly whining, a rare expression from her former professor.

Her voice is weak and broken, she’s become so needy, and Mercedes seems to enjoy knowing that she has the power to deliver, and seems to enjoy drawing it out so that she can tease her. Perhaps being teased is part of the pleasure that she intends to show Byleth, drawing it out so she will come even harder when she finally allows her to finish.

Whatever the case, Byleth has felt at her limit for some time now, and yet Mercedes continues to draw it out, forcing her to hang on and denying her her release until she is ready to allow it. Finally, she presses her tongue inside of Byleth, and Byleth cries out for her, calling her name as her tongue begins to delve deeper, seeming to know exactly how and where to target her, just to make her scream even more. The detached and reticent woman becomes a moaning mess whenever she goes to pieces in the bedroom, something that is becoming very easy for Mercedes to exploit.

And Byleth calls out her name again and again, unable to say anything else, and the more she says her name, the less coherent it becomes, until one can only be certain that she’s saying ‘Mercedes’ again because it all she has been able to say up to this point. But her ability to actually enunciate the syllables has faded away, and she knows only that she will not be able to hold out much longer. Mercedes knows exactly how to use her mouth and her fingers to make Byleth completely weak, to make her fall apart, and as she works her tongue inside of her and rolls her nipples between her fingers, Byleth is soon unable to withstand it any longer.

Arching her back again, she can’t help grinding up against Mercedes’ face a bit, her need finally overwhelming her so much that, in an instant, it’s all over for her. With a cry even louder than any of her previous ones, she gives in to her pleasure and comes so hard that she sees stars, crying out a mangled mess of syllables that is meant for Mercedes, completely oblivious to anything going on in the world around her as she rides out the waves of her pleasure.

She is dazed for several seconds after that, and when she starts to recover and come to, Mercedes is smiling down at her again. “I hope that was really good,” she murmurs, and Byleth can only nod, still too dazed to speak. Mercedes brightens even more and says, “Wonderful! Well, maybe now we can come and let our husbands get involved!”

They never state outright that she will be with Dimitri while Byleth will be with Dedue again, but they never have to. Mercedes climbs off of Byleth and goes to Dimitri with that same bright and welcoming smile on her face, one that he can only meet with a somewhat sheepish smile of his own. Meanwhile, Dedue comes over to join Byleth, and she grows excited as she remembers the effort that goes into getting her prepared.

Dimitri has lubed up his own fingers and Mercedes bends over eagerly to take them, while Dedue kneels on the bed behind Byleth, pushing her spread legs back so that he can begin fingering her hole. His finger is cold and slick again, but, just like before, slowly warms as he works it inside of her. Though she is still tight around him, it is an easier fit than before, perhaps because she remembers just how good it is, and is so eager for more of that. Whatever the case, Dedue soon has one finger buried inside of her, and when he moves it, she lets out a low and needy cry.

Mercedes has begun moaning rather regularly as well, and it’s a wonderful sound to hear, giving Byleth no choice but to try to angle her head so that she can see the look on her face. It is an expression unlike anything she has ever seen on Mercedes before, so lewd and shameless that it makes Byleth feel even weaker and even more needy as a result.

It is around this time that Dedue begins working a second finger into her, as if sensing just how needy she has become. Byleth longs to feel as full as possible and longs for the feeling of him pounding her in the ass with his huge cock, squirming as she imagines it. Dedue fingers her until she doesn’t think she can take anymore, arching her back up and whimpering for him.

She wonders how far Dimitri has made it with Mercedes, if he’s made it to two fingers yet, or if they go even farther, and that idea excites her even more. If she could catch her breath enough to speak, she might ask Dedue to add another finger, if he’s really going to take his time fucking her like this, but she can only let out more incoherent moans, so she has to be content with what she has.

Fortunately for her, it isn’t long until the three of them begin to decide on their position, a complicated one that makes proper use of the large bed. Byleth will remain flat on her back, with Dedue pushing her legs up to fuck her while standing just at the end of the bed, and Dimitri will kneel behind Byleth’s head, with Mercedes bent over directly over top of her. The women will be face to face while each taking the cock of the other’s husband, and that thought is unbearably thrilling to Byleth.

Dimitri begins to push inside of Mercedes first, once they’re both in proper position, and Byleth is able to watch the way her face shifts and contorts as he pushes forward and she begins to grow used to the new fullness. Mercedes bites her lip, and Byleth finds herself biting her own reflexively, so entranced by the sight.

That is when she feels the tip of Dedue’s cock pressed against, and she moans softly, eager for more. He is not as slow as he was before, as she is able to take is easier than she was the first time. Her eagerness and her knowledge that relaxation makes it easier and more pleasurable help, and it isn’t long before Dedue is completely buried inside of her, not long after Dimitri fully buries himself inside of Mercedes.

They can both look into each other’s eyes as they’re fucked, and Byleth finds that she can’t look away once Dimitri begins thrusting forward, and Mercedes cries out in pleasure. She’s so beautiful like this, Byleth thinks, until she loses her train of thought entirely as Dedue mimics Dimitri, jerking his hips forward to begin thrusting into her.

The men manage to fall into opposite rhythms, Mercedes and Byleth jerking forward and back opposite each other, and for a bit, the women can only lose themselves in the pleasure of finally being fucked, but Mercedes is able to gather her thoughts a bit quicker than Byleth, and wants to do more. She supports her weight with one arm so that she can move her other hand down, and Byleth lets out a sharp cry as Mercedes begins stroking at her clit.

It is enough to send electrifying shocks of pleasure up and down her spine, and she knows that she won’t be able to last long like this, no matter how she tries. She gets brief seconds of relief from the overwhelming stimulation whenever Dedue pulls back, preparing to thrust forward again, because Mercedes will move her hand to tease at his cock until he does. Then, she will return her attention to Byleth’s clit again, and Byleth will cry out and nearly lose all control.

Naturally, she isn’t able to last very long under these conditions, and it only takes a few attempts of this before she’s sent over the edge, her body wracked her orgasm, her mind so hazy that it takes her a moment to process that Dedue has come as well. She feels the wet warmth of his seed and slowly realizes that he has finished, clearing her mind enough that she is able to look up and see the delicious expression Mercedes makes as she reaches her own climax. Dimitri groans a few seconds later, following right behind her.

Tonight the other couple doesn’t leave their bedroom. Instead, once the four of them have gotten cleaned up, they collapse in a heap in the bed, much too large for just two people to share. It goes unspoken, but they silently agree to spend the night together, falling asleep in a heap.

**Author's Note:**

> If you're interested in my writing updates, please follow my fanfiction twitter @WattStalf  
> 


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